1) Change these 5 APIs to void type:
vcpu_inject_pf
uart16550_calc_baud_div
uart16550_set_baud_rate
console_init
ptdev_activate_entry
No need to return 'entry' for ptdev_activate_entry
since the input parameter is 'entry'.
2) no need to check return value for the caller
such as sbuf_put/console_putc/serial_puts/serial_get_rx_data
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>